president obama will also visit columbus, ohio, and des moines, iowa, today. the president will spend tonight in chicago where he'll await the results of the election. >> mitt romney will visit four battleground states today. he's in virginia right now and will appear at george mason university this afternoon. the republican presidential nominee will also head to ohio, new hampshire and florida, all today. police are calling it a horrific accident. the pittsburgh zoo remains closed the day after a 2-year-old boy fell into a wild dog exhibit and was mauled to death. police say the boy's mother tried to give him a better view by putting him up on top of the railing of the viewing deck but the 2-year-old fell 11 feet into the pit. they say a pack of african painted dogs attacked him immediately. zookeepers say they did everything they could to save the little boy but it was too late. >> they responded immediately and were able to get several of the dogs into the backup building. the veterinarians arrived and tried to scare the dogs away from the young child with